Module etc. rexexp fixes and cleanup (#1861)

[rlarv]

meant for issue #1861
indentation problem when there is a signal named "module_something"

cleanup:
remove a superflous extra \> end-of-word delimiter

fixes:
use shy-grouping \(?: \) to fix \< and \> begin/end-of-word
which were accidentaly not used for each alternative in some \| regexp

!!! beware of "assert" !!!
I might have broken that by adding bow and eof regexps.
May be something like \<assert\(?:_always\)?\>
or something even longer, should be used here

[wsnyder]

Looks good, one minor fix (that was broken before).

[wsnyder]

Suggested change

	(verilog-re-search-backward "\\<\\(?:\\(fork\\)\\|\\(join\\(_any\\|_none\\)?\\)\\)\\>" lim 'move)
	(verilog-re-search-backward "\\<\\(?:\\(fork\\)\\|\\(join\\(?:_any\\|_none\\)?\\)\\)\\>" lim 'move)

[rlarv]

Yes, of course, that gets rid of one unused "group".
Of course there are more such unused groups, for example the \(un\) groups for "unsigned".
And there is this nice "rx" macro of emacs which would improve readabilty and maintainabilty quite a bit.
Some info is here https://www.emacswiki.org/emacs/rx
For example
(rx bow (or (group "fork") (group "join" (opt (or "_any" "_none")))) eow)
or even
(rx bow (or (group "fork") (group (or "join" "join_any" "join_none"))) eow)
which yields and even optimizes a bit to
"\\<\\(?:\\(fork\\)\\|\\(\\(?:join\\(?:_\\(?:any\\|none\\)\\)?\\)\\)\\)\\>"
at macro expansion time.
But I think this is not available in xemacs.
Regards,